The invention relates to activities involving a plurality of participants where participants are required to follow specified standards of behavior such as a code of conduct. The participants may be humans or may be automated agents or automated services. A participant may also be two or more humans or agents working together. For example, the activity may be a game which may be provided online or in a conventional manner. In another example the activity may be a market or auction which may or may not be provided online. A common problem observed in such activities is that the standards of behavior are not met or are deliberately abused by some participants to the detriment of other participants in the activity. In some situations this may even lead to the breakdown of the activity as a whole. Some degree of trust is required between participants in order to ensure that the activity can succeed.
This problem is particularly exacerbated in the case of online activities or communities such as online chat rooms, electronic markets and virtual multiplayer game worlds. Conventional mechanisms for ensuring standards of behavior are met, such as legislation, written contracts, escrow services and the like cannot always be used for such online activities. For example, the transaction amounts in online market places are typically very low so that use of written contracts is prohibitively expensive.
History, reputation or rating systems have been used as a means of promoting trust between participants in activities and this is particularly the case for many online activities such as online market places. For example, existing online market places provide a reputation system which is a simple cumulative registry of user ratings and feedbacks on a given market place member. For example, each feedback is accompanied by either a positive, neutral or negative rating and these ratings may be combined in a simple manner. However, this simple system is open to abuse in situations where for example, many positive ratings are given in a fraudulent manner.
For example, consider an online gaming service whereby participants are able to play online games with one another. It is known to enable players of online games to leave positive or negative feedback on other players whom they have participated with in an online game. However, it is difficult to make use of this feedback information because it is often inaccurate. For example, some players always leave negative feedback irrespective of their actual experience in a particular game. Other players always leave positive feedback even when this is not warranted. Similar problems arise in other situations, for example, in online market places where participants leave feedback about the behavior of vendors and/or purchasers.